The instant invention relates to a tool for cutting pipe and more particularly to a rotary cutting tool for cutting the wall of a pipe from inside the pipe through an opening at one end of the pipe.
It is common practice in the building construction industry for plumbers to install large diameter pipe, such as plastic waste pipe, before finish flooring is installed. The pipe is left overlong so that it may be cut down to the necessary level of the finish floor as required after the floor has been finished. If this level is above the finish floor, the pipe may be cut simply with a hacksaw. Generally, it is necessary to cut off the end at a level below the level of the floor for proper connection of a water closet, shower pan, or bathtub. There is not enough space around the pipe at the desired level to admit a hacksaw. The pipe is often cut away with a chisel or other hand tool which is awkward, labor intensive and may leave an irregular cut end. The problem has been recognized for some time, and U.S. Pat. Nos. 4,369,573 issued in January 1983 to Vitale; 4,177,559 issued to Anderson; and 4,177,558 issued to Brown in December 1979; 3,999,292 issued to Breese in December 1976; 3,911,574 issued in October 1975 to Jones; and 4,466,185 issued in August 1984 to Montiero provide rotary cutters that attempt to solve the problem.
The patented devices provide a variety of mechanisms for controlling the depth of cut to ensure cutting completely through the wall without extending beyond the outer wall and mechanisms for controlling the path of the cutting tool.
They are all quite complex so that they are difficult to operate, and expensive. The plumber is not anxious to invest in an expensive tool that has so limited an application so that most plumbers still use awkward hand tools that they already have in their toolboxes for other purposes even though they are not well suited to this application.